This invention relates to a method and composition for repairing cooling systems of combustible engines and the like and particularly for sealing cracks in such devices as heating cores, freeze plugs, radiators, cracked or warped heads and blown head gaskets. The most common approach generally taken to repair such cracks is to utilize solid particles carried by a liquid for conveying the particles to the cracks. In this conventional approach the solid particles act as plugs for sealing the cracks. A difficulty with this conventional approach is that it is applicable only to large cracks with varying effectiveness but is not effective with respect to very small cracks which are too small for the particles to enter. Another disadvantage with such conventional techniques is that such techniques operate too slowly.
A variation of the above-conventional techniques which have been considered is to completely omit the solid particles as the sealant and instead to use as the sealant a pure liquid. In this variation the liquid flows into all cracks and openings whether large or minute. The components of the liquid are such that upon the application of heat, such as by starting the engine, the liquid solidifies and thereby is intended to close or seal the cracks.